For example, in a photolithography process of a semiconductor device manufacturing method, a series of processes such as a resist application process for forming a resist film by applying a resist solution onto a wafer, an exposure process for exposing the resist film into a specified pattern, and a developing process for developing the exposed resist film is performed one after another to form a specified resist pattern on the wafer. The series of processes is performed by an application development system as a substrate processing system in which various kinds of processing units for processing the wafer and transfer units for transferring the wafer are installed.
In recent years, a circuit pattern formed on a wafer has been miniaturized and a defocus margin at the time of exposure has become more stringent. One of the causes for defocus includes, for example, adherence of particles to a stage of an exposure device. A major cause for generation of these particles is that the particles adhere to, particularly, a rear surface of a wafer transferred into the exposure device. For the above reason, prior to transferring the wafer into the exposure device, the rear surface of the wafer may be cleaned by a cleaning device installed within an application development system.
In the cleaning device, cleaning is performed by moving a brush pressed against the rear surface of the wafer while the rear surface of the wafer faces downward, for example, by attracting and holding the rear surface of the wafer.
In some cases, unevenness due to flaws and the like generated on the rear surface of the wafer may be a cause of defocus. Therefore, prior to transferring the wafer into the exposure device, the rear surface of the wafer may be polished by a polishing device as will be described below.
In the polishing device, polishing is performed by pressing a polishing pad against the wafer while supplying a polishing liquid to the wafer. The polishing pad is then retreated from above the wafer and a cleaning brush is moved onto the wafer. In order to remove polishing sludge or the like from the wafer, the wafer is cleaned by the cleaning brush while supplying a cleaning liquid.
Since the throughput in a photolithography process is typically dominated by the throughput of an exposure device, a throughput of the above described cleaning device and the like is required to be higher than that of the exposure device. However, the throughput of a typical cleaning device or a typical polishing device may be lower than that of the exposure device. Thus, for example, for one exposure device, a plurality of cleaning devices and the like may be installed within an application development system.
In addition, from the viewpoint of the running cost and the like of a clean room, the footprint of the application development system is required to be set as small as possible. Thus, a space for installation of a cleaning device or a polishing device may not be necessarily sufficient in the application development system. Thus, the polishing process or the cleaning process may be a bottleneck.
In this case, the polishing pad for the polishing process and the cleaning brush for the cleaning process may be installed within one device. In that case, however, controlling an arm for operating the polishing pad and an arm for operating the cleaning brush becomes complex. In addition, since drive devices for operating the arms are installed individually, the space required to install the drives devices becomes larger. Thus, space saving is not sufficient.